Fluid operated jacks have been utilized in applications for moving a load engaging implement, for example, an ejector of a load carrying machine, between spaced apart load carrying and load ejecting positions relative to a load carrying body of the machine. The fluid operated jack is often operatively connected to and between the load engaging implement and telescopically extensible to move the load engaging implement between the extended and retracted positions. It has been found that the amount of space required between the load engaging ejector and the load carrying body to house the jack substantially reduces the load carrying capacity of the load carrying body and makes such configuration unattractive.
Attempts have been made to alleviate this problem but have all resulted in an unsuitable solution. For example, in U.S. Pat. No. 3,815,764, to William C. Gilfillan et. al., dated Jun. 11, 1974, the jack is disposed in a protective tubular member mounted on the load engaging member and axially oriented in the direction of movement of the load engaging member. The protective tubular member extends to one side of the load ejecting. The jack is connected to the load engaging implement by way of a trunion mounting assembly on the other side of the load engaging member. This configuration helps to reduce the space required between the load carrying body and the load engaging implement. However, because the trunion mounting cantilevers the jack, the amount of clearance between the cylindrical housing of the jack and the protective tubular member is substantial. This is required to accommodate manufacturing and operating tolerances and prevent side loading of the jack during extension of the jack. As a result, the size of the tubular member and supporting structure is massive, takes space, and subsequently reduces the amount of load carrying capacity of the load carrying body.
The fluid operated jack of the Gilfillan et. al. Patent is held by the trunion mounting so that the cylinder housing carrying the other telescopic jack sections is restrained from rotation about the longitudinal jack axis. Since the longitudinal axis is maintained substantially horizontal, premature wear of the cylinder, seals, and other related components will occur on the low side of the components (beneath the longitudinal axis). This wear results in leakage of the fluid operated jack.
Other configurations have been tried to provide a jack for powering movement of a load engaging member which appear to attempt to solve the above discussed problems. For example, in U.S. Pat. No. 3,941,260, to Don H. Fisher et. al., dated Mar. 2, 1976, the fluid operated jack is at an angle (not horizontal) relative to the load engaging member. This configuration addresses some of the problems associated with having a horizontal fluid operated jack. However, this configuration reduces the load carrying capacity of the load carrying body, is not as efficient or effective in power transfer and smoothness of operation and requires a higher fluid pressure or a larger diameter jack to apply an adequate or equivalent force to the blade.
The invention is directed at overcoming one or more of the problems set forth above.